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 A078838 a(n) = Sum_{k=1..(p-1)*(p-2)} floor((k*p)^(1/3)) where p is the n-th prime. 0

%I #14 Mar 02 2023 21:30:17

%S 0,2,30,120,630,1122,2760,3978,7392,15498,19140,33390,46020,53382,

%T 70380,102102,142158,157530,210210,251160,273492,348348,405162,501468,

%U 652080,737550,782952,879270,930258,1038072,1480500,1626690,1863540

%N a(n) = Sum_{k=1..(p-1)*(p-2)} floor((k*p)^(1/3)) where p is the n-th prime.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeSums.html">Prime sums</a>.

%F a(n) = (1/4)*(3*p-5)*(p-2)*(p-1) where p = prime(n).

%o (PARI) a(n) = my(p=prime(n)); sum(k=1, (p-1)*(p-2), sqrtnint(k*p, 3)); \\ _Michel Marcus_, Mar 01 2023

%K nonn

%O 1,2

%A _Benoit Cloitre_, Dec 08 2002

%E Name edited by _Michel Marcus_, Mar 01 2023

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Last modified September 24 00:14 EDT 2023. Contains 365554 sequences. (Running on oeis4.)